The present invention relates to an improved method for drying trinitrotoluene (TNT).
TNT is an explosive having a solidification temperature of about 80.degree.C. It is produced either batchwise or continuously. Regardless of how it is produced, the last process step is a hot water wash of the melted TNT. After the water has been separated, the TNT contains water in minor amounts which has to be removed before the subsequent cooling (flaking).
One precautionary main principle in explosive manufacture is to keep the amount of explosive in each stage on the lowest possible level. This is performed in order to reduce the effect of a possible explosion accident. Examples in this connection are the introduction of continuous nitrating and washing processes for TNT, such as, e.g., described in Norwegian patent specification No. 93,255 and U.S. Pat. No. 3,087,971, as well as the emulsion storage of nitroglycerine.
For the drying of TNT several methods may be used. A usual method is to pass the melted TNT into an iron container equipped with a heating mantle, and to pass air through the charge through perforated tubes until the charge is free from water. Using this method may provide a concentration of several tons of TNT in the drier. Another method, which is more advantageous, especially in connection with continuous nitrating and washing processes, comprises passing the material through a vessel in a forced direction and passing air through perforated tubes into and through the material. The amount of explosives in such driers varies, but generally is in the range of about 400-600 kgs., and, thus, provides greater safety relative to batch-operations.